4.3 Carbon cycle

Question 1

Carbon Dioxide diffusion

Answer 1

From atmosphere into ocean.

Aqueous CO₂ binds to H₂O to form H₂CO₃ –> H + HCO₃^- (Hydrogen Carbonate)

Carbonate ions are used by coral to form the skeleton base (CO₃^2- )

Carbonate ions bond to H to form HCO₃^-

HCO₃^- makes the water more acidic.

Question 2

Carbon cycle features

Answer 2

Pools (producers, consumers, detrits, Fossil fuels)

Flux (Arrows that show direction of Co2)

Question 3

Methane

Answer 3

CH4

Oxidized to CO2 and H2O in the atmosphere

CH₄ + 2O₂ –> CO₂ + 2H₂O

Question 4

Peat

Answer 4

Forms when organic matter is not fullt decomposed because of acidic and/ or anaerobic conditions in waterlogged soils.

Question 5

Limestone

Answer 5

Forms from fossilized calcium carbonate in corals.

Is sedimentary rock.

Question 6

factors impacting Co2 in atmosphere

Answer 6

• Combustion (burning of fossil fuels)
• Deforestation
• Volcanic activity
• Seasons (photosynthesis)
• Forest fires
• Ecosystems developing into climax conditions

Question 7

when is Co2 released

Answer 7

plants, microbes, animals respire

burning fuels

Question 8

Carbon fixation

Answer 8

Conversion of inorganic carbon to organic carbon by living things (photosynthesis)

Question 9

Cell respiration

Answer 9

Conversion of organic carbon back into inorganic carbon

Question 10

Processes that affect the carbon cycle

Answer 10

• Methane production
• Peat formation
• Coal and oil formation
• Combustion
• Limestone formation

Question 11

Methanogenesis

Answer 11

Methane is the product from organis matter in anaetobic conditions by methanogenic archaens, some diffuses into the atmosphere

Question 12

Oxidation of Atmospheric Methane

Answer 12

CH4 + 2O2 -> Co2 + 2H2O

Question 13

Combustion Sources

Answer 13

Fossil Fuels

• The heat and pressure over time triggers a chemical transformation that results in the compaction of the organic matter
• results are coal, oil and natural gas (non renewable)
• Organism decomposed NOT fossilised

Biomass
- An alternative to relying on fuels produced by geological processes is to manufacture fuels from biological processes
- Living organisms produce hydrocarbons

Question 14

The ocean

Answer 14

Acts as a large reservior for carbon.

Dissolved Co2 in seawater occurs as 3 inorganic compounds:
- Aqueous Co2
- Bicarbonate (HCO3-)
- Carbonate ions (Co3^2-)

Question 15

carbon dissolving in seawater process

Answer 15

Co2 binds to H2O

carbonic acid (H2Co3) is formed

It then splits to form H & HCo3-

Increased atmospheric Co2 = increased dissolved Co2 in seawater
= decreased carbonate available for corals

Question 16

Coral formation

Answer 16

Carbonate ions (Co3^2-)are absorbed by coral and molluscs to form calcium carbonate (CaCo3)

Calcium carbonate is used to form the hard exoskeletons of reef-building corals and is used by molluscs to develop shells

Question 17

Construct a carbon cycle diagram

Answer 17

Question 18

Autotrophs

Answer 18

Autotrophs convert carbon dioxide into carbohydrates and other carbon compounds